The objective of these studies is to develop a valid in vitro assay system in which biochemical events in the crown-gall tumor formation process can be efficiently studied and changes at this level ordered in time. The appearance of two unique tumor compounds, octopine and nopaline, changes gamma-aminobutyric acid levels, and changes in the enyzmes of their metabolism will be studied as biochemical markers of the transformation process in chopped tissue incubated with the tumor inducing bacterium. Based on assays of the enzymes responsibile for synthesis of octopine and nopaline, of gamma-aminobutyric acid-alpha-ketoglutarate transaminase and changes in soluble proteins as determined by gel electrophoresis, the variation in these components in time will be used to establish optimum conditions for, and synchronization of, the conversion process. BIBLIOGRAPHIC REFERENCES: Whatley, M.H., J.S. Bodwin, B.B. Lippincott and J.A. Lippincott. 1976. Role for Agrobacterium cell envelope lipopolysaccharide in infection site attachment. Infect. Immun. 13: 1080-1083. Spiess, L.D., B.B. Lippincott and J.A. Lippincott. 1976. The requirement of physical contact for moss gametophore induction by Agrobacterium tumefaciens. Amer. J. Bot. 63:324-328.